Enhancing the polarization of spin levels at room temperature is one of the active research areas in magnetic resonance. Generation of electron spin hyperpolarization involves a complex interplay of electronic and spin processes. In this work, the optimization of crucial electron spin polarization (ESP) generating parameters and synthesis of a radical−chromophore adduct are described. The ESP of the synthesized adduct is about 550 times the equilibrium polarization at room temperature, which is possibly the maximal value for a chromophore−nitroxyl system. The present work highlights the crucial role of the photophysical quenching process toward the generation of a large ESP. Additionally, a chromophore−diradical adduct is synthesized, and the effects of the additional radical in the ESP generation process are discussed. Enhanced photochemical stability is demonstrated for the diradical adducts, thereby suggesting a potential route toward the generation of photostable radical−chromophore adducts for future studies. The large ESP in these molecules should enable a wide range of applications, such as in DNP, spintronics, and magnetometers.